After crashing an experimental aircraft, Air Force pilot Carol Danvers is discovered by the Kree and trained as a member of the elite Starforce Military under the command of her mentor Yon-Rogg.
Law could indeed play Mar-Vell, but also Yon-Rogg. That could be exactly the kind of twist the company would to hide. Over on the IMDB page for the film, Jude Law is billed as playing Walter ...